This invention relates to hydrogenation processes. In another aspect, the invention relates to hydrogenation of acetylenic compounds. In a further aspect, the invention relates to the stereospecific hydrogenation of acetylenic compounds.
For a hydrogenation process to be useful on a large scale, catalysts must be available which are readily and inexpensively prepared, give selective reaction, and have high reactivity over an extended period of time. Prior art hydrogenation catalysts employed for the hydrogenation of functionally-substituted acetylenic compounds have a variety of drawbacks which prevent their use on a large scale. Thus, for example, catalysts employing platinum or palladium are very expensive and readily lose activity in the presence of various functional groups; the preparation of catalysts such as Raney nickel is a relatively tedious process. In addition, some hydrogenation catalysts display low reactivity with functionally-substituted acetylenic compounds. Where prior art hydrogenation catalysts display high reactivity with functionally-substituted acetylenic compounds, a frequent problem is poor selectivity to the desired hydrogenated product, due, for example, to double-bond isomerization of the initially formed olefinic product, and/or undesired side reactions between the hydrogenation catalyst and the functional group of the reactant acetylenic compound (or product olefinic and/or aliphatic compounds).